Liquid-fuel stove



G. E. PICKUP LIQUID FUEL STOVE Filed Deo.

April 28, 1931.

9, 1927 2 Sheets-Sheet l April 28, 1931. G.. E. PICKUP LIQUID FUEL sTovE Filed Dec. 9, 1927'` 2 Sheets-Sheet 2 mx .6N MJ.

,frac 'QTLZF/"f I @forger E Eck up 7 M @M -Patented Apr. 28, 1931 UNITED .STATES PATENT OFFICE GEORGE E. PICKP, OF NEWARK, OHIO, ASSIGNOR TO THE WEHRLE COMPANY, F NEWARK, OHIO, A CORPORATION 0F OHIO LIQUID-FUEL STOVE Application led December 9, 1927. Serial No. 238,827.

This invention relates generally to liquid fuel stoves wherein thc liquid fuel is delivered under pressure to a liquid fuel gas generating device, and more particularly has reference to a safety device therefor.

It is a general object of the invention, to provide a novel means to prevent the overflowing or flooding of the stove with liquid fuel shouldJ the fuel be permitted to o flow while the stove is inoperative.

Another object is to provide means operable, upon the accumulation of a predetermined amount of liquid fuel in the fuel gas manifold, to release the pressure under which the liquid fuel is maintained, whereby further feeding of liquid fuel is immediately prevented.

A further object is to provide an inherently safe device of this character which,

after once having been actuated, positively prevents further operation of the stove until an operator has manually reset the device.

Other objects and advantages will become apparent in the following detailed description of the preferred embodiment of the invention and from the accompanying drawings, in which:

Figure 1 is a fragmentary plan section of the upper portion of a cook stove embodying a preferred form of the invention, showing the liquid and gaseous fuel supply lines and conduits and the control means therefor. y

Fig. 2 is an enlarged detail in section taken on the line 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a side elevation partially in section showing the liquid fuel supply pressure tank.

Fig. l is a detail view of the preferred form of the means for stopping and preventing the passage of liquid fuel from the supply tank.

Fig. 5 is a fragmentary elevation partially in section of the means for generating gaseous fuel from the liquid fuel.

Fig. 6 is a section along the line 6 6 of Fig. 3.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling Within the spirit and scope of the invent1on as expressed in the appended claims.

The invention has reference generally to the type of cook stove described in my copending application Serial No. 161,476, filed January 17th, 1927, in which liquid fuel is delivered under pressure from a supply tank to a gas generating means for conversion into fuel gas. Referring to the dra-wings, 6 designates generally a stove frame of the usual well known construction having mounted in an open top section a fuel gas manifold 7 leading through various 70 extensions 8"to a plurality of burners (not shown) and 'supplied with the fuel gas from a suitable gas generator 9. As may be seen in Figs. 1, 2 and 3, the gas manifold is formed, preferably near one end, to provide I5 a relatively small downwardly extending pocket 10 which is, in effect, a trap Within which any liquid fuel present in the manifold will accumulate, he purpose of which will be hereinafter apparent.

The gas generator 9 may be of any suitable cliaracter, but that which is herein depicted is substantially the same as that shown and described in my above-mentioned copending application. Briefly, said gas y e5 generating means comprises a generator tube 11 arranged to receive liquid fuel under pressure from a supply tank 12 through a pipe line 13. The tube 11 is connected to the manifold 7 and the passage of fuel 90 from the tube into the manifold is controlled y by a needle valve 14 manually operable by the handle 15. During operation of the stove, fuel gas for combustion in the burners is generated in the tube 11 by means of a 95 sectional burner 16 underlying and extending laterally of the tube 11 and supplied with fuel gas from the manifold 7 through the extension 8a. An auxiliary burner 17 controlled by the valve 18, is provided for n heating the generator tube 11 when a burner which heats a remote portion of the stove, such as the oven, is used and it is not desirable to operate the main enerating burner 16. The initial lighting o? the stove necessitates the use of a pregenerating unit 19 (Fig. 5) which comprises a coil 20, preferably of copper tubing, positioned beneath the generator tube near the front thereof and arranged to be supplied with liquid fuel through the fitting 21. The coil terminates in a jet tip 22 which is directed to play substantially over the coil 20 and the lower surface of the generator tube. The liquid fuel passing to the coil is controlled by a valve 23 so that when the pregenerating coil 20 is initially heated, as by means 0f a match, a small quantity of liquid fuel may be admitted to the coil which fuel is converted into gas and ignited. The iame thus generated initially heats the coil to create an increased quantity of gas and within a comparatively short time sufficient heat is supplied thereby to vaporize the liquid fuel in the generator tube 11. At this point the needle valve 14 may be opened to permit the generated fuel vapor to pass into the manifold, which vapor is immediately conducted through the manifold 7, the extension 8a to the burner 16 and ignited by the iiame from the pregenerating unit, which may then be shut off.

It will be apparent that in the type of stove which has been thus far described it is possible that during the lighting operation, a quantity of liquid fuel may readily be carried or forced into the manifold. Moreover, the valve handle 15, controlling the needle valve 14, may accidentally become opened and since the liquid fuel is fed thereto under pressure, there will be a resulting flow of tin` liquid fuel into the manifold, and thence to the burners to overiiow or iiood the stove. Or, in another instance, the generatirg burners may become extinguished and permit liquid fuel to pass into the manifold.

In any event, whether the liquid fuel accumulates gradually in the manifold or Whether it flows rapidly thereinto, the presence of the liquid fuel in the manifold is a serious disadvantage since it may necessitate the draining and cleaning of the manifold, extensions and burners before the stove can be used again. To overcome this disadvantageous feature, means have been provided in association with the liquid fuel supply tank from which the fuel is delivered to the gas generator under pressure, whereby, when a predetermined quantity of liquid fuel has accumulated in the gas niacifold, the pressure in the supply tank is re1 leased to prevent further feeding or supplying of the fuel therefrom.

The fuel tank l2 is of a character generally well known and is secured rigidly to one side of the stove frame 6 as by suitable brackets 24. The tank, as before mentioned, is connected with the generating tube 11 by means of the pipe line 13 which has the inlet thereof positioned near the bottom of the tank. The tank may, if desired, be provided with various control gages such as the pressure gage 25 and a fuel gage 26 and means, such as the cut-olf valve 27 may be provided in the pipe line 13 to regulate the passage of fuel from the tank.

A cap 28 adapted to fit over the front end of the fuel tank to form a continuation thereof provides an enclosed chamber within which is mounted a hand pump 29. The pump is of an ordinary construct-ion adapted to build up a suitable feeding pressure within the tank 12 and comprises a cylinder 30 within which a piston 31 reciprocates. The piston is operated by means of a piston rod 32 pivotally secured at its outer end to a handle 33 which is pivotally mounted, as at 34, to a suitable support, such as one of the brackets 24, on the tank. The handle extends forwardly of the tank and stove frame for ready manipulation by an operator in pumping air into the tank. An air line 35 leads from the pump to a cap 36 upon the upper surface of the tank, which cap also serves as an aperture through which the tank may be filled with liquid fuel. A valve 37, manually operable by means of a handle 38, is incorporated in the air line 35 to close the line after suiiicient operating pressure has been created in the tank.

In the present embodiment the control device 39 (Figs. l, 3 and 4) is mounted on a suitably formed support 40 fixed, as by means of the screws 41, on the stove frame, preferably near the fuel supply tank. A vent 41 is mounted rigidly on the support and comprises, in this instance, an L shaped tubular member having one end open to the atmosphere and provided at the other end with a suitable nipple or fitting 43. A tubular vent line 44 connects the nipple 43 with the air line 35 connecting the pump 29 with the pressure tank at a suitable point which, in this instance, is shown as being adjacent the air line control valve 37 on the side remote from the pump. Thus, when the vent 42 is open, an exhaust passageway from the air chamber portion of the pres sure tank to the atmosphere is provided. The invention provides a mechanism for normally closing the vent 42 during the operation of the stove, which mechanism is arranged to open said vent if, for any reason, liquid fuel should flow into the manifold 7 in appreciable quantities. Thus, as shown in Figs. 3 and 4, a rod 45 is mounted for reciprocation through a pair of suitable supporting and guiding brackets 46, 47. The direction of reciprocation of the exhaust passage, and in the other )osition of the rod the pad is spaced there rom to open the vent and exhaust the air in the tank.

Intermediate the tubular nut and the adjacent bracket 46 a. collar 50 is slidably mounted upon the rod and a helically coiled spring 51 is positioned about the rod to bear between the tubular nut 48. and the collar. On the opposite or outer end of the rod a second helically coiled spring 52 is mounted, which bears between the outer bracket 47 and a suitable means rigid with the rod, such as a pin 53. It Will be seen by this construction that the helical spring 51 exerts a force when under tension and moves the rod to position the pad against the open end of the vent and effects a closing thereof. The second helical spring 52 exerts a force which, when tension has been removed from the first helical spring, moves the rod in the opposite direction to open the vent. Preferably the valve closing spring 51, which maintains the valve in closed position, is substantially more powerful than the valve opening spring 5 2 since, in closing the valve, the spring 51 must irst overcome the tension of the opening spring 52.

Means by which the valve mechanism is moved into and held in engagement to close the vent is provided, which means in this instance preferably comprises an arm 65, is swingably mounted upon a pivot 66 carlried by the support 40 at a suitable point at one side of the valve mechanism. The upper end of the arm is in the form of a yoke 67, the side members of which straddle the rod-45 and are positioned to bear against the outer end of the collar 48 so thatswinging movement of the arm will move the collar to tension the closing spring 51 whereby the valve mechanism is moved to cause the valve to close the vent. The free end of the arm is arranged to provide a finger piece 68, at its extremity and has thereon a. laterally extending shoulder 69 (Fig. 6) the purpose of which will be hereinafter apparent. By this construction a swinging movement of the arm 65 in one. direction will close the valve, and in the other direction operates to open the valve and permit the release of pressure through the vent.

The means for actuating the valve and by which the valve is automatically opened comprises an interlocking i engagement which must be manually set to maintain the valve closed and which is automatically released or tripped, upon the accumulation of a predetermined amount of liquid fuel in the manifold, to open the valve. In the present embodiment the means, whereb automatic release is effected, comprises a lever 54pivotally mounted to swing upon a suitable pivot 55 extending outwardly from the support 40 at a point below the vent 42 and its associated closing mechanism. As shown (Figs. 3 and 4) the lever extends substantially parallel to the rod 45 and carries-at one end a laterally extending rod 56 from which a receptacle or cup 57 is suspended for relative swinging movement. The other end of the lever carries a counterbalancing weight member 58 which is sufficiently heavyV normally to maintain the empty cup in a raised position (Fig. 3). A pair of spaced stops 59 may be provided upon the support 40 to limit the swinging movement of the lever.

The outer end of the pivot"55 carries a latching member 60 in the form of a plate swingably held thereon by suitable means such as the washer 61 and pin 62. The latching member 60 extends substantially parallel in spaced relation to the lever 54 and on one end is notched, as at 63, preferably at a point adjacent the pivot 55, which notch is adapted to engage the shoulder 69 on the arm 65. The end 64 of the latch, beyond the notch 63, is tapered and the arrangement of the parts is such that the shoulder 69 is adapted to slide over the tapered surface into engagement with the notch 63, in which position the valve is held in closing engagement with the vent 42.

As may be seen in the drawings the other end of the latching member 60 extends sub stantially parallel to the lever 54 to a point opposite the counterbalancing weight 58, at which point a vertical slot- 70 is provided in the member. The counterbalaneing weight carries an outwardly extending pin 71 rigid therewith arranged to extend through the slot, in the latching member. By this construction it will be seen that in the swinging movement of the lever 54, past a certain predetermined point, the pin 71 will engage the latching member 6() at the upper end of the slot 70 therein and will move the latching member about its pivot to release the engagement between the notch 63 thereon and the shoulder 69 on the arm. The slot and pin engagement permits a limited relative movement between the lever and the latch member, thereby preventing accidental disengagement of the device which might be causedby vibration, sudden jars or the like. The release of the arm from its holding engagement with the latching member releases the tension on the closing spring 51 and gferthe .ately over the cup 5 'l mits the opening spring 52 to move the valve ont of engagement with the vent.

As shown in Fig. 1, the pocket 10 formed on the manifold 7 for receiving the liquid fuel which passes thereinto is provided with a suitable nipple 72 and a draln or duct 7 3, connected thereto leads through the frame of the stove to a discharging position immedihe drain 73, as shown in Fig. 2, preferably slopes upwardly to some extent adjacent its connection with the manifold to form a liquid trap whereby the escape of fuel gas from the manifold will be prevented.

The operation of the device is exceedingly simple. Assuming the stove to be in opera tion and that for any reason li uid fuel has been discharged into the mani old, such liquid Will immediately find its way into the pocket 10, thence through the drain 73 to be discharged into the cup 57. When a certain amount of liquid, which amount is determined by the weight necessary to lift the counterbalance weight 58, has been discharged into the cup 57, the cup and lever 54 will swing downwardly to the position shown in Fig. 4. As the counterbalancing weight 58 moves upwardly the pin 71 carried thereby will engage the slot to release the interlocking engagement between the arm 65 and the latch member 60. The release of the interlock permits the valve to be moved out of engagement with the open end of the vent permitting the pressure within the tank to be immediately exhausted therethrough. Even after the stove has been shut off, the liquid fuel in the manifold, with the exception of the small amount necessary to provide the liquid trap in the pocket 10. continues to drain through the duct into the cup until the manifold is empty. After the device has been actuated, it is first necessary to empty the liquid fuel from the cup, then reestablish the engagement between the latch member and the arm to close the vent before pressure can be created in the supply tank to again place the stove in operating condition.

It will be apparent from the foregoing description that a device has been provided which is inherently safe since it is impossible to place the stove in operation after the control device has once functioned until after the necessary steps have been taken to reset the device. Moreover, the device is simple, easy to operate, and positively insures against the presence of any other than a very small quantity of liquid fuel in the gas compartments of the stove.

I claim as my invention:

1. In a liquid fuel stove, in combinati. n with a liquid fuel supply tank adapted to supply fuel under pressure and a fuel gas manifold, a control device for preventing the accumulation of liquid fuel in said manifold, said control device comprising a pressure exhaust 'vent connected to the fuel tank, a pivoted arm having means on one end thereof normally closing the open end of said vent, a pivoted lever having a. receptacle carried on one end thereof, a counterbalancing Weight carried by the other end of said lever, a latch connected to said lever and normally adapted to engage said arm to maintain said vent closed, and a drain connected to said manifold and adapted to convey accumulated liquid fuel from said manifold to discharge into said receptacle whereby the weight of the liquid discharged will swing said lever to release the normal engagement between said latch and arm and to open said vent.

2. A cooking stove for burning gasified liquid fuel, said stove comprising, in combination, a frame, a fuel supply tank on said frame for containing liquid fuel under gas pressure, a generator, a supply pipe for conveying liquid fuel under pressure from said tank to said generator, a plurality of burneis adapted to burn gaseous fuel, one of said burners being arranged to heat said generator to gasify the liquid fuel supplied thereto, a manifold connected to said generator and to said burners so as to receive the gasiied fuel and distribute it to the burners, a trip mechanism including a receptacle, a drain having a liquid trap therein arranged to conduct unburned liquid fuel from within said manifold to said receptacle, said trip mechanism being operable upon the accumulation of a predetermined amount of liquid in the receptacle to release the pres- Sure in said fuel supply tank and thereby prevent further feeding of fuel.

3. A cooking stove for burning gasitied liquid fuel, said stove comprising, in combination, a frame, a fuel supply tank on said frame for containing liquid fuel under gas pressure, a generator, a supply pipe for conveying liquid fuel under pressure from said tank to said generator, a plurality of burners adapted to burn gaseous fuel, one of said burners being arranged to heat said generator to gasi the liquld fuel supplied thereto, a manifo d connected to said generator and to said burners so as to receive the gasified fuel and distribute it to the burners, a trip mechanism including a re ceptacle, a drain arranged to conduct unburned liquid fuel from within said manifold to said receptacle, a vent valve connected to the gas space of said fuel tank, said trip mechanism being operable upon the accumulation of a predetermined amount of liquid in the receptacle to open sail vent valve to release the pressure in said fuel supply tank and thereby prevent further feeding of fuel. l

4. A cooln'ng stove for burning gasifie( liquid fuel, said stove comprising, in combination, a frame, a fuel supply tank for containing liquid fuel under gas pressure, a vent passageway opening into said tank above the normal level of liquid therein, a Valve member for closing said vent passageway to maintain pressure in said tank, a burner arranged to burn gasified liquid fuel, a generator heated by said burner and arranged to receive liquid fuel under pressure from said tank and to gasify said fuel, a receptacle havingr a connection with said generator to receive fuel therefrom in a liquid state, means for releasably holding said valve in its vent closing position, and a device operable to release said means upon accumulation of a predetermined amount of liquid fuel in said receptacle.

5. In a control device for liquid fuel stoves having a burner and a vaporizer supplying fuel vapor to the burner, the combination with a fuel tank, means for creatinfr pressure in the tank to supply liquid Lfuel to the vaporizer, of a vessel for collecting liquid fuel discharged by the vaporizer in unvaporized condition, a lever operated by the liquid in the vessel, and a valve controlled by the lever and controlling the pressure in the fuel tank to release the pressure therein upon rise in the fuel level in the vessel.

6. In a stove, the combination of a burner, a vaporizer receiving heat from the burner, a fuel tank below the level of the burner, means for creating air pressure in the tank for delivery of liquid fuel to the vaporizer to be vaporized thereby, a connection for conducting fuel vapor from the vaporizer to the burner, means for collecting fuel discharged from the vaporizer in liquid condition. upon failure of the burner to deliver heat thereto, and a control device between the burner and the tank and actuated by said collected liquid fuel to shut olf the flow of fuel from the tank by release of the air pressure in the tank.

. 7 In a stove, the combination of a burner, a vaporizer receiving heat from the burner, a fuel tank below the level of the burner and normally containing air under pressure for delivering fuel from the tank to the vaporizer, a connection for conducting fuel vapor from the vaporizer., to the burner, a sump for collecting fuel discharged from `the vaporizer in liquid condition upon failure of the burner to deliver heat thereto, and a control device connected to the sump and to the tank for receiving collected liquid fuel from the sump and operating to shut olf the ilow of fuel from the tank by release of pressure in the tank upon rise of the fuel level in the device.

8. In a stove, the combination of a burner,

Va fuel tank below thel level of the burner -the burner to accomplish said vaporization,

means for collecting fuel discharged from said vaporizing means in unvaporized condition upon failure of said vaporizing means, and a control device for receiving said collected liquid fuel and operating to release the pressure in said tank upon receiving. a predetermined amount of said collected fuel.

9. A cooking stove for burning gasiiied liquid fuel, said stove comprising, in combination, a fuel supply tank, a generator to gasify said fuel and to which liquid fuel is fed from said supply, a manifold arranged to receive fuel from said generator, a drain from said manifold having a liquid trap therein, and a safet device connected to said drain and opera le by a predetermined quantity of liquid fuel delivered thereto by said drain to prevent further feeding of fuel to said generator.

In testimony whereof, I have hereunto afixed my signature.

GEORGE E. PICKUP. 

